Circular polarization biomicroscopy: a method for determining human corneal stromal lamellar organization in vivo

Abstract

The theory of polarization biomicroscopy is explored using Stokes vectors and Mueller matrices. It is established that circular polarization can be used to simultaneously detect birefringent elements at any orientation unlike orientation-sensitive techniques using linear polarized light alone. A method of biomicroscopy using circular polarized light is described and tested in a physical model. The method is then used to investigate the lamellar structure of human corneas in vivo in pairs of eyes of 38 subjects. An approximate confocal elliptic/hyperbolic distribution of stromal fibrils, presumed to be collagen, is clearly identified within central and intermediate areas of the cornea. All subjects tested demonstrate approximate mirror symmetry between pairs of eyes typically with a preferred orientation of central fibrils at approximately 15 degrees to the horizontal in a superotemporal-inferonasal direction.

Polarization microscopy for characterizing fiber orientation of ocular tissues

“…PLM has been proven effective to characterize collagen of tendons [20,21], ligaments [22] and other soft tissues [23]. The possibility of using PLM in the cornea was discussed almost two decades ago for ex-vivo tissues [24], and more recently to study the cornea stroma in vivo [25]. However, the accuracy, repeatability and robustness of the technique when applied to ocular tissues remains to be determined.…”

Modeling the corneal birefringence of the eye toward the development of a polarimetric glucose sensor

“…Several research groups have reported on the behavior of birefringence in the peripheral regions of cornea. [19][20][21][22] Misson utilized circular polarization biomicroscopy to study corneal structure and birefringence. 19 Jaronski and Kasprzak devised a phase stepping imaging polarimetry technique to measure the birefringence of human cornea in vitro, and concluded that corneal birefringence increases monotonically in the direction of the corneal periphery.…”

“…[19][20][21][22] Misson utilized circular polarization biomicroscopy to study corneal structure and birefringence. 19 Jaronski and Kasprzak devised a phase stepping imaging polarimetry technique to measure the birefringence of human cornea in vitro, and concluded that corneal birefringence increases monotonically in the direction of the corneal periphery. 20,23 Hitzenberger, Gotzinger and Pircher employed polarization sensitive optical coherence tomography to map the distribution of birefringence at the posterior corneal surface.…”

A New Noncontact Tonometer Using Corneal Photoelasticity: Porcine Eye Study

“…He suggested the possibilities of IOP measurements without contacting the eye with any transducer, but there were no further studies done. Recently, Misson [4] reconfirmed that colored, approximately diamond-shaped rings with horizontal and vertical apices were present at the human corneal periphery due to its photoelasticity. The centrifugal progression of color of the peripheral rings matched that expected up to the second-order interference colors from increasing retardation due to a graded rise in birefringence.…”